Mass mailings have long been referred to as "junk mail." Not surprisingly, recipients of such mailings have often been inclined to simply dispose of the mailings without even opening the envelopes. This situation has been disappointing to advertisers who routinely invest tremendous resources in mass mail advertising campaigns. The cost of a mass mail advertising campaign is usually justified by the customer response generated by the mailing The situation described above is therefore particularly troubling to advertisers because recipients who altogether refuse to open the envelopes are certain to be non-responsive to the advertising campaign
Accordingly, advertisers have tried to modify the external appearance of their mailings so that they would be less readily identifiable as such. For example, envelopes with glassine windows, through which the recipients' names and addresses appeared, have been replaced by more formal looking closed-faced envelopes, on which the names and addresses are printed Also, advertisers have changed the contents of the mailings from unpersonalized brochures and the like to personalized letters and memoranda printed with the recipients' name and address and other personalized identifying information. The advent of high-speed laser printing has facilitated the creation of personalized inserts for mass mailings, making the overall aesthetics of the mailing very appealing to a recipient.
While aesthetically pleasing and personalized mass mailings have enjoyed a substantially higher customer response rate, the cost of preparing such mailings has been much more than unpersonalized mailings. The added cost has been due in large measure to the efforts expended to ensure that all personalized material for a given recipient is assembled into an envelope for that recipient. Conversely, the added cost has arisen from ensuring that personalized material for one recipient does not get mixed up with personalized material for another recipient. The added cost, for example, has been in the form of additional employees to manually verify proper collation, slower production, down-time and re-working costs when an assembly error is detected.
Various attempts to reduce the costs of personalized mailings have centered around electronically verifying that the personalized material intended for a given recipient is properly matched. For example, specialized markings such as bar codes or similar arrays of dots and dashes or the like have been printed on personalized envelopes and inserts for optical scanning to verify proper matching. This approach, while workable, has suffered from a number of shortcomings. First, the bar codes or markings degrade the aesthetics of the mailing, detracting from the benefits of having a personalized mailing in the first instance. Second, in the event of a mismatch in production, the bar codes or markings, which are not human-readable, provide no guidance to an operator whose task it is to re-work a sequence of mismatched items. Third, if an attempt is made to reduce the negative impact of a bar code or similar marking by reducing the size of the code or marking, then the same identifying mark would need to be reused periodically. For example, every sixteenth mail item would have the same identifying mark, which could result in a substantial amount of mismatched mail should an error in production occur.